American military commanders said that Britain repeatedly failed to secure its
part of Helmand province in Afghanistan, leaked diplomatic cables have
disclosed.

The extremely high levels of violence in Sangin, where 106 British soldiers have been killed, reflected a failure to concentrate forces and mount decisive attacks against the Taliban, US commanders are said to have believed.

Britain handed over control of the town in northern Helmand in September.

The American criticism of Britain’s departure from Sangin, which was leaked to the WikiLeaks website, has raised painful memories of the withdrawal from Basra in Iraq, where US commanders made clear they believed the Army had failed.

Any suggestion that Britain left Sangin after a military failure would be an embarrassment for Coalition ministers, who have strongly defended the redeployment as a sensible reorganisation.

Some American commanders have also criticised British operations elsewhere in Helmand, including a secret peace deal negotiated in 2006 with insurgents around the town of Musa Qala.

British sources accepted that some American commanders and officials had been critical of Britain’s record in Sangin before the hand-over. But they insisted that the leaked cables did not reflect the current US view.

One source said: “The Americans’ initial comments were quite harsh. But that changed very quickly once they actually got to Sangin and started operating there.”

When the US forces arrived in Sangin, they began to dismantle a network of towers and remote outposts built by the British. That decision was taken as a rebuke to the British forces, who lost several men capturing the territory to build the outposts. Almost a third of the total number of British troops killed in Afghanistan died in Sangin.

British sources said that the Americans have since begun reconstructing some of the posts. As well as the US verdict on Britain’s forces, the leaked papers have also made a range of revelations about Washington’s dealings with Kabul.

The US envoy to Afghanistan has said those revelations could have “potentially cataclysmic fallout” for relations with Hamid Karzai, the Afghan president. Karl Eikenberry told his Canadian counterpart in Kabul that secret messages disclosed by WikiLeaks could feed Mr Karzai’s paranoia and deepen his confrontational stance towards Nato.

William Crosbie relayed the American concerns to his government in Ottawa in a diplomatic memo which was then leaked. Mr Crosbie said some feared Mr Karzai would “burn his bridges” with the coalition once the cables emerged.

WikiLeaks documents have already stated Washington’s belief that Mr Karzai’s brother is a corrupt drug baron. There was also frustration at presidential pardons for well-connected drug traffickers.

A Ministry of Defence spokesman said British forces left Sangin with honour. “UK forces did an excellent job in Sangin, delivering progress by increasing security and taking the fight to the insurgency.

“That work is being continued by US marines who have publicly recognised and paid tribute to the sacrifice and achievements of UK forces.”